OK,I've been back at playing on a regular basis for about a year now, and I'm getting close to where I was when I stopped twenty-some years ago. My particular frustration is articulating the upper (Clarion) B & C...Altissimo is no problem, and up to the Bb in the clarion is ok, but all I get is "fuzz" or squeaks on the B & C. Have tried different mouthpieces, instruments, & reeds, and nothing fixes it...However, with some reeds it's a lot closer. SO my question is, is there a particular place on the reed that I can adjust to make these notes speak more easily? I have butchered many reeds trying to fix this.

I doub't your problem is with the reed. Since you have no problems except with the Clarion B and C, I suspect it's an instrument problem. Check the upper joint for hole contamination and pad condition. If you can play fine throughout all other registers including the altissimo, then it has to be a problem in the upper joint. Very weird though.

1)If anything wrong with upper register pads,they will be those positioned higher than the register key.
2)Register key elevation may be too big.It should be less than 1.2mm.
3)Clarion B or C should be emitted with lower lip deeper using right hand thum.

IMHO, I don't think your problem is in the reed, especially if you can get altissimo and the rest of the clarion to behave themselves on your horn. I also don't believe that you have a mouthpiece or ligature problem either for this same reason. Areas I'd check include keypads and balance points. There are some other issues, including the possibility of "shading" fingerings that could affect high clarion note playability. Let me explain.

Fetch an inexpensive cigarette paper and check out your pads. If the paper resists pulling away smoothly as you close the keypad, then you probably have a decent keypad and a good acoustic seal on that tone hole. If it gets some additional resistance in any particular direction, then you may have a leaking pad. Check for a leak in the F# pad that's directly under the A key. It's a sneaky little devil that most folks overlook. Ditto for the G# keypad and the A keypad right next to it. Check to make sure that the A key is adjusted properly and that it closes and seals both the G# and A keys totally, yet plays A in tune. Also, take the time to inspect and clean the thumb hole, using a pipe cleaner to make sure there is no crud buildup there. As Hiroshi said, check the register key for proper opening. Check its keypad, too. Check its tube and make sure it's clean. Since the high clarion and altissimo notes depend on the upper side Bb and B trill keypads sealing totally, so check these out, too. If every keypad is working properly and you are still having the problem, then there is another set of issues to study.

The upper clarion B and C give you very little fingering support for the rest of the horn, so consider how you are holding the horn in your right and left hands as you play these notes. Think about resting the horn (if it's a soprano clarinet, as I'm guessing here) on your knee and try playing the notes then. If this gives you some help, then you may have a hint as to how to gain more physical control over the fulcrum points (see-saw pivot areas) of your horn, thus giving less stress on your embouchure to hold the horn in place and play it, too. The main trick in this last hint is to let your hands take on the weight of the horn instead of your lips.

I've discovered that my professional grade horn with its undercut toneholes requires a lot more accuracy in fingerings. For instance, I can't be lazy and have my fingers too close above the tone holes without totally sealing them, because the resulting note comes out really sour. This is known as "shading" the note. The high clarion notes, especially the clarion C and B have a particular sensitivity to shading. Let's face it, how many times have you fingered the right thumb, left first finger and right first finger for clarion Bb? If you are like me, a bunch of times. It also works (one at a time, of course) with the right second finger and the right third finger. It even works with just pressing down on the uppermost keypad (next to the rh first finger tone hole) on the lower joint, too. This makes for a great sounding altissimo Eb on my horn. So, check for accurate fingerings. Then, take a look at the return spring across your upper and lower joints and check for that uppermost keypad on the lower joint for proper opening/sealing as needed with just the clarion B fingering.

These were all of the tricks I could remember from years of lessons with my professional tutor. Keep in mind that he did all of the tricks mentioned above after he helped me with the mp/lig/reed, embouchure, air support and everything else in those areas. I figured if fetching the services from a person with a clarinet performance degree from a nationally ranked music school, Daniel Bonade training, 25 years in a major city symphony, and another 25 or so years of independent gigs couldn't fix my squeaking and squawking, then nothing could. I'm still an adult novice, but I sure have learned a lot over the past few years.

Thanx for all those suggestions. The horn is an old (probably 30-40 years)Leblanc that I've had since high school, so I had the best clarinet repair person in the area (rcommended by our professional first-chair Symphony player) go over all the pads & keys about 2 mos. ago, and even had a cork pad put on the register key. So it could still be pads, and I'll check again, but I'm really afraid it's me. I do have undercut tone holes, and I know that precise fingering makes a difference, but I have trouble getting the C to speak even when I stop, position everything consciously, and try to begin the tone with my tongue. I'll double check with the weight of the horn on my knees--I play this way occasionally when my right wrist starts acting up. I'm not sure how to measure the register key clearance--it sounds like you need a special gauge, like a feeler gauge for spark plugs? Next, I guess, will be professional help in the form of lessons, if not psychotherapy!

The register key clearance doesn't require exact measurement in the micrometer range. Here's a quick (somewhat inaccurate, but quick) way to see if your register key opens about right is to use a simple small ruler. Press your register key down all the way and measure the keypad's clearance from its tone hole. If its 1mm to 1.5mm (about 1/2 inch) away and the altissimo speaks okay, then stop. If it opens 2 to 2.5 mm (about an inch), then it's great for throat Bb, but terrible for altissimo.

Again, check for register tube and thumb hole clogging, too.

As for seeking professional advice, I'd side with the tutor instead of psychotherapist. Though if your tutor is a good friend, perhaps (s)he can listen to other problems, too. This is no joke. Let me explain...

Just to be fair, I've had very similar problems with the low altissimo not being able to speak for me, either. The notes just won't come out for love or money. My tutor noticed that I tensed up to prepare for the altissimo - a little psychological battle that I lost every time. He saw that I nearly strangled myself with tension in my throat, cutting off the air supply from the top down. I figured out this problem for myself by working the three register drill and related scales drills until the psychological barrier dissolved. Perhaps you may need to do the same thing for your problem.

paul wrote:
-------------------------------
If its 1mm to 1.5mm (about 1/2 inch) away and the altissimo speaks okay, then stop. If it opens 2 to 2.5 mm (about an inch), then it's great for throat Bb, but terrible for altissimo.
-------------------------------

Your conversions are way off. It takes 25.4mm to make an inch. So 1mm is about 0.040" and 2.5mm is about 0.1"

I have NEVER seen a register key open as far as 1/2 an inch let alone a full inch!

OK, the register key is about 1.5mm, definitely less than 2 mm by my drugstore ruler. Already checked for crud. Yes, I know I tense up and I think therein lies (some of) the rub. But I'd like for it to be a mechanical problem because that's easier to fix. But there's no question that some reeds allow me to get closer and with others there seems to be no hope. Right now, I'm suspicious of the throat A & Ab pads, because they don't seem to be as tight, but the F# is fine.
Thanks for all the detailed help.